▼ Circularly polarized luminescence (CPL), the emission analogue to circulardichroism (CD), reflects the chirality of materials in the excited electronic state. CPL active materials with efficient performances are essentially suitable as emitters for optoelectronic devices for stereoscopic optical processing, display and storage, and sensors for chiral recognition in pharmaceutical industries and biological systems. However, compared to standard photoluminescence spectroscopy, CPL spectroscopy is less studied. Typically, CPL is generated when a luminophore experiences in a dissymmetric environment in the excited state and thus inevitably requires helical arrangement of the luminophoric molecules. The ordered assembly of the luminogens, however, results in reduced emission efficiency owing to the notorious aggregation-caused quenching (ACQ) effect suffered by most conventional chromophores. Therefore, overcoming the ACQ effect is a key step towards the design and fabrication of efficient CPL emitters. An excellent phenomenon opposite to ACQ was discovered in 2001 by our group: a series of nonluminescent molecules are induced to emit efficiently by aggregate formation [aggregation-induced emission (AIE)]. It is envisaged that AIE luminogens can possess improved CPL performance. Attracted by the intriguing phenomenon and its fascinating perspectives, I have launched a new program directed towards the development of new AIE materials with circularly polarized luminescence (CPL). In order to induce the helical arrangement of the AIE luminogens, chiral peripheral groups including sugar and amino acid are used to functionalize the silole core. The resultant molecules are capable of self-assembling into helical structures which have high fluorescent quantum efficiency and remarkable CPL signals. Interestingly, different fabrication methods leading to different morphologies can change the preference of either left- or right-handed circular signals. One of the examples also shows that the preference can be tuned through the addition of enantio-pure mendalic acids. In addition, facile oxidative coupling reactions are employed to construct new type of AIE luminogens with different functionalities.

Ng JCY. Development of new materials with aggregation-induced emission and circularly polarised luminescence. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2013. [cited 2019 May 25].
Available from: https://doi.org/10.14711/thesis-b1252011 ; http://repository.ust.hk/ir/bitstream/1783.1-81397/1/th_redirect.html.

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ng JCY. Development of new materials with aggregation-induced emission and circularly polarised luminescence. [Thesis]. Hong Kong University of Science and Technology; 2013. Available from: https://doi.org/10.14711/thesis-b1252011 ; http://repository.ust.hk/ir/bitstream/1783.1-81397/1/th_redirect.html

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

► The emergence of metamaterial opens up the opportunities to systematically study electromagnetic phenomena. By designing specific structures, certain new properties can be found and these…
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▼ The emergence of metamaterial opens up the opportunities to systematically study electromagnetic phenomena. By designing specific structures, certain new properties can be found and these properties are absent in the materials alone. The most famous example is that by using a twisted structure, electric and magnetic resonances can be excited and hence giving rise to negative refractive index. This new property is just one of the potential applications of metamaterial. In this thesis, circulardichroism and circular conversion dichroism are the focused electromagnetic phenomena to be studied. For the theoretically part of this thesis, fundamental relations on Jones matrix (transmission matrix) causing circulardichroism and circular conversion dichroism are derived based on transpose symmetry. The relation on Jones matrix causing asymmetric transmission is also derived. The derived relations are then investigated through experimental and simulation results of a crossed grating (experiment are done by Vincent Gao in my research group) which consists of two metallic gratings separated by a buffer layer and a twisted angle. By comparing experimental and simulation results to the derived fundamental relations on Jones matrix, it is demonstrated that (1) asymmetric transmission comes from asymmetric structure, such as asymmetric ·SiO2 buffer layer, which is different when viewed from forward and backward direction, alld (2) the dips in transmittance are attributed to parallel or anti-parallel resonant current modes which are excited differently by RCP and LCP waves depending on chirality of crossed grating. However, the simulation results start to deviate from the experimental results when twisted angle is less than 45°. In the simulation results, more oscillations are observed when compared to the experimental results. The exact reason for this behavior is still not known.

► Metamaterials are artificially designed and fabricated materials which derive novel properties from structures on the sub-wavelength scale. Two dimensional (planar) chirality and three dimensional (bulk)…
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▼ Metamaterials are artificially designed and fabricated materials which derive novel properties from structures on the sub-wavelength scale. Two dimensional (planar) chirality and three dimensional (bulk) chirality are two important electromagnetic properties of chiral metamaterials. Motivated by some potential applications such as giving rise to negative refractive index, the research on chiral metamaterials is developing fast in recent years. In this thesis, circular dichroisms have been carefully studied. Theoretically, with the help of the Jones matrix method, two kinds of circular dichroisms, circular conversional dichroism and circular conversion dichroism, have been distinguished; experimentally, I have fabricated saw tooth structure metamaterials on indium tin oxide (ITO) coated glass, and cover the sample with another ITO coated glass to eliminate the asymmetric transmission. As a result, the circular conventional dichroism and the circular conversional dichroism could be distinguished. What is more, considering the requirements in application, a series of control variable experiments have been done to study the effects of the metamaterials' thickness, pattern stripe width and lattice type on circular dichroisms. Our experiments prove that the circular conversion dichroism do exist in saw tooth metamaterials, for both of the uncovered (3D asymmetric) and sandwiched (3D symmetric) samples. The control variable study also paves the way for fabricating metamaterials with high transmission and large circular dichroisms, these results might benefit the applications of metamaterials.

► In this study we have used isothermal titration calorimetry, ITC, and circulardichroism spectropolarimetry, CD, to directly measure the thermodynamics and the structural changes for…
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▼ In this study we have used isothermal titration calorimetry, ITC, and circulardichroism spectropolarimetry, CD, to directly measure the thermodynamics and the structural changes for binding histones, H11 and H14, to DNA. The ITC data have been used to estimate the binding constant, (K ≈ 108) and the enthalpy change (ΔH ≈ + 5 (H11 at 25ºC), ΔH ≈ +20 kcal/mol (H14 at 15 ºC) for formation of the H1/DNA complex. CD data indicate that both H1 and DNA are partially unfolded in the H1/DNA complex. Protein and DNA unfolding must contribute to the large unfavorable endothermic enthalpy change for complex formation. The ITC data indicate that the H11 binding site is comprised 30 DNA base pairs while H14 interacts with approximately 36 DNA base pairs. At saturation, our data are consistent with 100% of the H1 binding sites being occupied in the H1/DNA complex.
Advisors/Committee Members: Edwin A. Lewis (chair).

►CircularDichroism (CD) and Linear Dichroism (LD) spectroscopies measure the difference in absorption between left and right circularly polarized light and parallel and perpendicular linearly…
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▼CircularDichroism (CD) and Linear Dichroism (LD)
spectroscopies measure the difference in absorption between left
and right circularly polarized light and parallel and perpendicular
linearly polarized light as a function of wavelength respectively.
CD and LD are popular biomedical physics techniques used to
determine structural changes in biomolecules. This dissertation
addresses improvements made to the measurement of CD and LD signals
by characterizing the transfer function of the spectrometer. Shot
noise stray light and dark current were characterized. A new model
for the measurement of the CD signal involving the presence of
static birefringence was derived and tested by implementation of
novel techniques used to measure the phase-difference amplitude and
static birefringence in the photoelastic modulator (PEM) crystal.
The model was tested by measuring the fractional change in the
signal on Camphorsulfonic Acid (for CD) and Chrysazin (for LD). It
is hoped that this study will impact how CD and LD are measured and
analyzed in the future. ; Physics, Camphorsulfonic Acid,
Chrysazin, Noise, Photoelastic Modulator
Advisors/Committee Members: John M. Kenney (advisor).

► Vibrational circulardichroism (VCD) spectroscopy has been utilized to reveal the detailed conformational distributions of the dominant serine species and leucine species in aqueous solutions…
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▼ Vibrational circulardichroism (VCD) spectroscopy has
been utilized to reveal the detailed conformational distributions
of the dominant serine species and leucine species in aqueous
solutions under three representative pH conditions, together with
vibrational absorption (VA) spectroscopy, density functional theory
(DFT), and molecular dynamics simulation. For both serine and
leucine, the experimental VA and VCD spectra in H2O and D2O in the
finger-print region at three pHs have been obtained. DFT
calculations at the B3LYP/6-311++G(d,p) level have been carried out
for the protonated, zwitterionic, and deprotonated species. In the
leucine case, preliminary results based on the comparison of the
experimental VA spectra of leucine in H2O and D2O in the
finger-print region to the simulated spectra of different leucine
species in the gas phase and with the polarizable continuum model
(PCM) are presented. In the serine case, the comparison between the
gas phase simulations and the experimental VA and VCD spectra
suggests that one or two of the most stable conformers of each
species contribute predominantly to the observed data, although
some discrepancies have been noted. To account for the solvent
effects, both the polarizable continuum model and the explicit
solvation model have been considered. The hydrogen-bonded
protonated, zwitterionic, and deprotonated serine-(water)6 clusters
have been constructed based on the radial distribution function
analyses and molecular dynamics snap shots. Geometry optimization
and VA and VCD simulations have been performed for these clusters
at the B3LYP/6-311++G(d,p) level. The detailed conformational
distributions of the dominant serine and leucine species at three
pHs have been investigated using VA and VCD spectroscopy together
with ab initio calculations. Inclusion of the explicit water
molecules has been found to improve the agreement between theory
and experiment noticeably in all three cases, thus enabling
conclusive conformational distribution analyses of serine in
aqueous solutions directly.

﻿The observation of ferromagnetism of (Ga,Mn)As by Ohno in 1998 has inspired great interest in diluted magnetic semiconductors (DMS). DMS’s features combining ferromagnetism and semiconducting…
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﻿The observation of ferromagnetism of (Ga,Mn)As by
Ohno in 1998 has inspired great interest in diluted magnetic
semiconductors (DMS). DMS’s features combining ferromagnetism and
semiconducting make them of great potential for conceptual
spintronic devices, which is a promising field of research for the
emerging electronics. The practical application of DMS requires a
Curie temperature well above room temperature and an intrinsic
ferromagnetism. There are several types of DMS materials. The
typical ones are transition-metal (TM) doped GaAs, GaN and ZnO. The
TM-doped ZnO has drawn particular attention due to the observation
of room temperature ferromagnetism in this system including
cobalt-doped ZnO.But the origin of ferromagnetic TM-doped ZnO is
still unknown after a decade’s theoretical and experimental effort
on this material.
In this thesis, we do the magnetic circulardichroism(MCD) and Hall measurement of high quality Cobalt-doped
ZnO thin films grown by molecular beam epitaxy (MBE). Room
temperature ferromagnetism is observed in these samples. Combining
the data from MCD and Hall measurement, we attribute the room
temperature ferromagnetism in this system to the impurity band of
the doped Cobalt cations.

Europium chalcogenides (EuX, where X stands for O, S, Se or Te) have very interesting and unique magneto-optical properties, due to the huge magnetism that arises from the electrons in the f?shell of the rare earth element and which makes them attractive for spintronics applications ( spin transport electronics or spin basedelectronics) In this work we investigate the band-edge optical absorption in high magnetic fields in the Faraday geometry for EuTe and EuSe in the ferromagnetic order attained at low temperatures. In thin layers grown by molecular beam epitaxy, an intense magnetic circulardichroism were observed. The doublet of absorption lines showed a separation by about 200meV in EuTe and 300meV in EuSe. Next, we developed a theoretical model for the interpretation of the absorption spectrum, based in the framework of the model of an electronic transition from a localized ground state 4f7({8}S7/2)) to an excited state formed by the core states 4f6({7FJ=0...6) and the electron extended state in the 5d(t2g) conduction band, yielding an excellent qualitative and quantitavie agreement with experiment.

▼ Analysis of the secondary structures of the standard proteins myoglobin, hemoglobin,
lysozyme and a-chymotrypsin by CD spectroscopy resulted in excellent agreement of
estimated fractional composition with that observed by x-ray crystallography. CD
spectroscopy was found to be very accurate for estimating a-helix and random coil
content, but considerably less so for estimating b-sheet. Conversely, FTIR
spectroscopic analysis of the same proteins proved to be more accurate for b-sheet
estimation than either a-helix or random coil. Overall, CD spectroscopy was found to
be superior to FTIR spectroscopy for the quantitative analysis of protein secondary
structure, however, the two techniques are highly complimentary for protein structural
studies. Both CD and FTIR methods were found to be useful for protein stability
studies, where CD is suited to analysing a-helix stability through CD222 protein melts,
and FTIR is capable of investigating protein aggregation phenomenon (together with
2D correlation spectroscopy) and b-sheet stability.
The anhydrobiotic AavLEA1 nematode protein was discovered to be a
natively unfolded protein with an extended tertiary conformation. From FTIR melt
experiments this protein was shown to resist temperature-induced aggregation and to
act synergistically with the trehalose disaccharide in retarding the aggregation of
cytochrome c. AavLEA1 was also shown to be capable of producing protein fibrils by
adopting a completely helical structure in the presence of high concentrations of TFE.
Additionally, titration with Ca2+ resulted in an increase of ordered secondary structure
and demonstrated AavLEA1’s ability to sequester cations.
A second nematode anhydrobiotic protein (P. sup DJ-1) was found to be
structurally very similar to the human DJ-1 homolog and exist as an a/b-mixed b-
sandwich protein. Stability studies revealed that P. sup DJ-1 showed considerable
temperature stability, both in terms of its helix domains and its resistance to
aggregation. The structure of P. sup DJ-1 was found to be unaffected by high
concentrations of H2O2, as was its temperature stability, leading to the conclusion that
this protein functions as a molecular chaperone to relieve oxidative and/or heat stress,
similar to current opinions on the functionality of the human homolog.[1]
The Rab11-FIP3 homo-dimer predicted coiled coil protein fragment was
confirmed by CD spectroscopy and TFE titration. For the Rab11-FIP2 homo-dimer,
mutation of the valine residue 456 and the leucine residue 457 to glycine residues was
found to destabilise the mutant relative to the wild-type. As such, these residues are
concluded to be of central importance in the formation of the coiled-coil cap that
protects the hydrophobic core from the aqueous environment.
References:
1 Shendelman S, Jonason A, Martinat C, Leete T, Abeliovich A.
DJ-1 is a redoxdependent molecular chaperone that inhibits alpha-synuclein aggregate formation.
Plos Biology 2(11):1764-1773, 2004.

Metalloproteinases/disintegrin (MD) isolated from snake venom are potent inhibitors of platelet aggregation and cell adhesion, processes involved in illnesses as cancer and thrombosis. MD belong to the PIII class of the metalloproteinase/disintegrin gene family and they are constituted by three domains: the catalytic domain, metalloprotease; disintegrin-like (D) and cysteine-rich (R). Some MD proteins are rapidly processed (producing the disintegrin-like/ cysteine-rich domains), while others MD are processed slowly. In this work, we studied the autolysis process of the MD isolated from the venom of Bothrops jararaca (bothropasin) and Bothrops alternatus (alternagin). Despite high sequence identity, alternagin and bothropasin showed different autolysis processes. The processing of the alternagin produces an intermediate…

The sucrose binding protein (SBP) belongs to the cupin family of proteins and is structurally related to vicilin-like storage proteins. In this investigation, SBP was…
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The sucrose binding protein (SBP) belongs to the cupin family of proteins and is structurally related to vicilin-like storage proteins. In this investigation, SBP was expressed in E. coli and large amounts of the protein accumulated in the insoluble fraction as aggregated, denatured protein. The refolding of the purified protein proceeded with a progressive removal of urea into the renaturation buffer, which contained an oxido shuffling system (2 mM reduced glutathione and 0.2 mM oxidized glutathione) and glycerol 5% (v/v) as a proteinstabilizing agent. The renaturation of the protein was assayed by using far-UV circulardichroism (CD), intrinsic fluorescence, and quenching by acrylamide, KCl and KI. The percentage of secondary structure of the renatured protein, which was calculated on the basis of the CD spectrum, was consistent with that obtained by theoretical modeling with a large predominance of beta-strand structure (42%) over the alfa-helix (9.9%). The fluorescence emission maximum of 303 nm for SBP indicated that the fluorescent tryptophan was completely buried within a highly hydrophobic environment. Nevertheless, tryptophan quenching by acrylamide, KI and CsCL and the respective Stem-Volmer (Ksv) constant of 23.5 +- 0.5 M-1, 16.1 +- 0.2 M-1 and 4.9 +- 0.1 M-1 indicate that the fluorescent tryptophan residues were quite accessible to the quenchers and hence exposed to the solvent. We also measured the equilibrium dissociation constant (Kd) of sucrose binding by fluorescence titration using the refolded protein. The low sucrose binding affinity (Kd = 2.79 +- 0.22 mM) of the renatured protein was similar to that of the native protein purified from soybean seeds. Collectively, our results indicate that the folded structure of the renatured protein is similar to the native SBP protein. As a member of the bicupin family of proteins which include highly stable seed storage proteins, it was of interest to determine the structural stability of SBP. The thermal and chemical denaturations of the protein were examined by monitoring changes in the CD spectra and in the intrinsic fluorescence of the renatured protein. Our results indicate that SBP remained folded to a similar extent in the presence or absence of 8 M urea or 6 M GdnHCl. Likewise, it was fairly stable to high temperatures. The high stability of the renatured protein may be a eminiscent property of SBP from its evolutionary relatedness to the seed storage proteins.

► The infrared vibrational absorption (VA) and vibrational circulardichroism (VCD) spectra of methyl lactate in carbon tetrachloride and methanol have been measured in the 1000-1800…
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▼ The infrared vibrational absorption (VA) and
vibrational circulardichroism (VCD) spectra of methyl lactate in
carbon tetrachloride and methanol have been measured in the
1000-1800 cm-1 region. Noticeable changes due to the solute
self-aggregation and solvent-solute intermolecular hydrogen-bonding
in the reported spectra have been detected. A series of density
functional theory (DFT/B3LYP/6-311++G**) and single point
MP2/6-311++G** energy calculations have been performed to identify
and to model the explicit hydrogen-bonded complex. Geometry search
and optimization have been performed for the most stable
conformers. The VA and VCD spectra of these complexes have been
simulated and compared with the corresponding experimental spectra.
A novel experimental apparatus has been set up in order to carry
out Fourier transform infrared-VCD measurements in cold rare gas
matrices. Some preliminary results obtained with this new setup and
the challenges in these experiments are discussed.

► The rotavirus NSP4 protein is the first described viral enterotoxin. Abundant data from our laboratory reveals that NSP4 binds both the N- and C-termini of…
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▼ The rotavirus NSP4 protein is the first described viral enterotoxin. Abundant
data from our laboratory reveals that NSP4 binds both the N- and C-termini of caveolin-
1 (aa2-31 and 161-178, respectively). Yeast two-hybrid and peptide binding analysis
mapped the caveolin-1 binding site to three hydrophobic residues within the amphipathic
a-helix, enterotoxic peptide domain (aa114-135). The research studies herein utilized
peptides to investigate the interaction between NSP4 and caveolin-1. Peptides were
synthesized corresponding to the amphipathic a-helix and caveolin-1 binding domain of
NSP4 (aa112-140) and to the N- (aa2-20 and 19-40) and C- (161-178) termini of
caveolin-1, and were utilized in structural and functional studies. Fluorescence binding
assays revealed that NSP4 (aa112-140) binds to the N-terminus (aa19-40) of caveolin-1
with a stronger affinity than the C-terminus (aa161-178). In addition, this assay further
delineated the NSP4 binding domain on caveolin-1 to aa19-40. Secondary structural
changes following NSP4-caveolin-1 peptide-peptide interactions were investigated by
circulardichroism analysis. Changes in a-helix formation were observed only upon interaction of the NSP4112-140 peptide with the C-terminal caveolin-1 peptide (C-Cav161-
178).
The NSP4112-140 peptide contains a potential cholesterol recognition amino acid
consensus (CRAC) sequence. Therefore this peptide was examined for cholesterol
binding. Results of the binding assay revealed NSP4 binds cholesterol with a Kd of 7.67
+/- 1.49nM and this interaction occurs via aa112-140. Mutation of amino acid residues
within the CRAC motif resulted in weaker binding affinities between each of the
corresponding mutant peptides and cholesterol.
NSP4 peptides containing mutations within the hydrophobic and charged faces of
the amphipathic a-helix, enterotoxic peptide and caveolin-1 binding domain of NSP4
were examined for changes in secondary structure as well as diarrhea induction in mouse
pups. Circulardichroism analysis revealed that mutation of hydrophobic residues
resulted in a decrease in a-helix formation, whereas mutation of acidic and basic charged
residues caused little to no change in a-helical content. When tested for diarrhea
induction in mouse pups, the peptides containing mutations of either the hydrophobic or
basic charged residues did not cause diarrhea. Taken together, the results of this
research suggest a complex interplay between NSP4 secondary structure, caveolin-1 and
cholesterol binding and diarrheagenic function.
Advisors/Committee Members: Ball, Judith M. (advisor), Payne, Susan (committee member), Schroeder, Friedhelm (committee member), Zimmer, Danna (committee member).

The steady increase in energy consumption and the depletion of fossil fuels has reawakened the interest in developing alternative energy sources that can compensate the…
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The steady increase in energy consumption and the
depletion of fossil fuels has reawakened the interest in developing
alternative energy sources that can compensate the growing energy
demands. This research utilizes sugarcane bagasse (SCB) as
lignocellulosic raw material for the production of ethanol and
ultrasound was incorporated to improve the conversion processes.
The substantial reduction in pretreatment time and temperature with
improved efficiency are the most attractive features of the
ultrasound-assisted alkaline pretreatment. The hydrolyzate obtained
was found to contain very less inhibitors, which improved the
ethanol production significantly. The SCB hydrolyzate was subjected
to fermentation and the yield obtained was 91.81% of theoretical
ethanol yield. The hydrolysate obtained was fermented using
Saccharomyces cerevisiae and about 90.66 % of the theoretical
ethanol yield was observed in 48 h of fermentation. The effect of
ultrasound on enzymatic hydrolysis and simultaneous
saccharification and fermentation of SCB was performed. The
reducing sugar and ethanol production were investigated with
different concentration of cellulase, % amplitude and treatment
time. The circulardichroism (CD) spectroscopy analysis was
performed to determine the effect of % amplitude on
and#945;-helical structure of cellulase and the results showed that
the % amplitude affected the and#945;-helical structure of
cellulase. The newlineresults concluded that the ethanol yield was
not only regulated by substrate but also by other components.
However, the hydrolyzate composition obtained from ultrasound
assisted hydrolysis was not up to inhibitory level. The ultrasound
enhanced both chemical and biological reactions and it would be a
suitable method to improve the production of ethanol from
lignocellulosic biomass. newline newline newline

► Studies on chiral prolinamide-terminated dendrons and dendrimers for their catalytic and chiroptical properties were undertaken. During the course of this research, a convenient multigram preparation…
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▼ Studies on chiral prolinamide-terminated dendrons and
dendrimers for their catalytic and chiroptical properties were
undertaken. During the course of this research, a convenient
multigram preparation of 4-chloropyridine-2,6-dicarbonyl dichloride
was developed. This material was utilized in constructing
intramolecularly folded pyridine-2,6-dicarboxamide-based dendrons
and dendrimers with chiral prolinamide termini. The design of these
supramolecular catalysts was based on concepts of preorganization
and cooperativity, which stems from the interworking of natural
enzymes. The chiral dendron catalysts were synthesized up to their
3rd generation and tested for their catalytic properties in
asymmetric direct aldol reactions. Some selected catalysis
experiments showed positive dendritic effects in terms of
enantioselectivity and diastereoselectivity. In addition,
structurally modified dendron catalysts using the
1,3-isophthalamide branching unit as well as 1st generation
dendrimer catalysts were prepared. These catalysts also exhibited
notable positive dendrimer effects. Circulardichroism (CD)
spectroscopic data on benzyl amine derivatives of these dendrons
and dendrimers indicated the presence of a generation-dependent
helical bias. The helical conformation was determined to be P from
the CD analysis together with computational CD investigations
conducted in collaboration with the Hadad research group. Crystal
structure of 1st and 2nd generation dendrons confirmed the syn-syn
conformations of pyridine-2,6-dicarboxamide focal point as well as
the P helical arrangement of the terminal prolinamide dendron for
G1.
Advisors/Committee Members: Parquette, Jon (Advisor).

► One of the most interested topic in ZnO series diluted magnetic semiconductor is the role of oxygen vacancies. It has been shown that the oxygen…
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▼ One of the most interested topic in ZnO series diluted magnetic semiconductor is the role of oxygen vacancies. It has been shown that the oxygen vacancies and interstitial hydrogen ions can be generated when introduced hydrogen gas during the film growth depending on the growth temperature. The main goals of this study are to understand the effect of the added hydrogen during the growth of pure ZnO and Zn0.95Co0.05O films on the generation of oxygen vacancies and the effect of oxygen vacancies on magnetic coupling.
Two series of films, ZnO and Zn0.95Co0.05O (CZO) films, were grown by a standard RF sputtering technique. N&K optical measurement indicates the optical transmittance is lower by increasing the percentage of H2 in the growth atmosphere, which is denoted as H2%. Because the total growth pressure may control the mean free path of sputtered particles and indirectly affects filmsâ thickness which affects the quality of crystal grains. It is found that the crystal quality is better for films grown at 50mTorr rather than that at 130mTorr. The oxygen vacancy may introduce shallow donor band that enhances the electric conductivity, the film grown at 50mTorr has a higher electric conductivity than that at 130mTorr, as well. One important result of present study is that the doping of Co in ZnO films may enhance hydrogen effect and generates more oxygen vacancies in CZO films when were grown at the same growth condition as the pure ZnO films. Therefore, CZO films shows strong optical scattering lowing the optical transmittance. MCD measurements manifest obvious deep curves around 34eV which indicate that both series of films exhibit magnetic coupling under an applied filed, in which, CZO has stronger magnetic strength. However, the MCD is linearly dependent on the external magnetic field indicating a paramagnetic coupling. No room temperature ferromagnetic are observed. One important result is that the existence of magnetic coupling in pure ZnO film indicates that oxygen vacancies may trap electrons and preserved certain magnetic moment.
Advisors/Committee Members: Hsiung Chou (committee member), Chun-Yu Hsu (chair), Shih-Jye Sun (chair).

► Understanding how a protein folds to its functional structure is a central question of biophysics that is still not completely understood. Proteins that reside in…
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▼ Understanding how a protein folds to its functional structure is a central question of biophysics that is still not completely understood. Proteins that reside in membranes face the additional complication of inserting into the lipid bilayer while forming the correct conformation. Membrane proteins are essential for a number of biological processes and many diseases are linked to misfolding of these proteins, so gaining a better understanding of how membrane proteins attain their native structures is of great importance to biomedical research. Although most membrane proteins in the cell require the assistance of folding machinery to be properly folded and inserted, β-barrel outer membrane proteins are capable of spontaneously folding to the native state in the absence of folding factors, indicating an intrinsic folding mechanism dependent only on the amino acid sequence and the membrane environment. We have investigated several aspects of the intrinsic folding pathway
for the model bacterial outer membrane protein OmpA, including the conformation and interactions of the aqueous unfolded state, the extent of secondary structure formation during the folding and insertion process, and the presence of off-pathway intermediates. In studying the conformations of the unfolded state, we found that the periplasmic domain of the protein, which has typically been ignored in folding studies, behaves as an independent folding unit and helps reduce the self-association of the unfolded transmembrane barrel domain. We also determined that the unfolded barrel domain has no regular structure and an expanded conformation, indicating that structure can only form upon interaction with a membrane. We next investigated the folding and membrane insertion of the OmpA β-barrel and developed a comprehensive kinetic model to describe the pathways and folding intermediates of the protein. CD measurements revealed a partially inserted, penultimate state with a higher content
of β-sheet structure than the native state. Based on our data and previous work we have proposed a detailed folding model for β-barrel proteins that is facilitated by the presence of defects in the lipid bilayer and secondary structure formation in the protein. We also identified several off-pathway intermediate states that give rise to additional exponential phases in the data.
Advisors/Committee Members: Shortle, David (advisor).

Rat liver nuclei were digested very briefly by the Ca^+2, Mg^+2 dependent…
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Photocopy of typescript.

Bibliography: leaves 174-182.

Microfiche.

xvi, 182 leaves ill. 29 cm

Rat liver nuclei were digested very briefly by the Ca^+2, Mg^+2 dependent Endogeneous Endonuclease. The digested chromatin was analyzed using exponential sucrose gradients. By plotting the weight average number of subunits released against digestion time, a slowing in the rate of change of chromatin fragments was found in the region of around six subunits. This suggested that the nucleosomes were possibly folded into a chain of discrete superstructures, with 6 to 8 subunits per superbead, and that the DNA between such superbeads was more susceptible to the nuclease digestion than the linker DNA between the nucleosomes. The conformational state of DNA. in the native chromatin and its subunits was analyzed by thermal denaturation and circulardichroism. Monophasic melting profiles were obtained for both the chromatin and its subunits, suggesting that the electrostatic stabilization of the DNA by the histones (HI, H2A, H2B, H3 and H4) was evenly distributed on the chromatin and its subunits. The chromatin and its subunits showed suppressed DNA ellipticities in their circulardichroism spectra. However, upon assembly of the nucleosomes to form a chromatin fiber, the ellipticity increased until the value of chromatin was achieved. We found that at least 8 nucleosomes were required to give the ellipticity of the chromatin, implying that the nucleosomes were possibly folded in an asymmetric fashion. An imidazole spin label (IMDSL) was used to study the accessibility and conformational state of tyrosines in both the nucleosome core particles and histone core extracted from chicken erythrocytes. About 40% of the tyrosines in the histone core can be labeled under nondenaturing conditions. However, less than 15% of the tyrosines in the nucleosome core particle can be labeled even at 200- to 300-fold molar excess of IMDSL. Conformational changes in the spin labeled histone core and nucleosome core particles due to external perturbations, such as urea, NaCl, pH and temperature, were studied. The nucleosome core was more sensitive than the histone core to urea denaturation. Several conformational transitions in the labeled nucleosome core were observed in the range of 1 mM to 2. 5 M NaCl. A small change was detected at 10 mM NaCl and three major transitions were found between 0.1 M to 0.6 M, 0.7 M to 1.8 M and 2 M to 2.5 M NaCl. The labeled nucleosome core particle appeared to be unaffected by changes of pH in the range of 4.5 < pH < 9.5. A thermal denaturation profile, obtained by the ESR method, showed that gradual conformational changes occurred within the inner histone core before the DNA melted. The mode of reconstitution of nucleosome core particles was studied. A mixture of spin labeled histone cores and core DNA was reconstituted by salt step-gradient dialysis. At each step of dialysis, the labeled proteins were examined by ESR. It was found that the histone core bound progressively to the DNA. in the range of 2 M…

► The pollen of mugwort is a major contributor to hay fever in Europe and North America. The chemical structure of Art v 1, the major…
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▼ The pollen of mugwort is a major contributor to hay fever in Europe and North America. The chemical structure of Art v 1, the major allergen of mugwort, has been elucidated. A notable motif in Art v 1 – characterized by clusters of contiguous â-arabinosides of hydroxyproline – was found to be a key recognition element for antibodies generated in response to the natural protein. This dissertation details the chemical synthesis of oligomers of â-arabinosides of hydroxyproline and the search to establish the minimal carbohydrate epitope of Art v 1. The â-arabinoside motif, being a 1,2-cis glycoside, presents a considerable challenge to organic synthesis. Methods for the stereoselective introduction of furanosides are not as well developed as for their pyranoside counterparts. The key issue pertaining to the formation of glycosidic bonds is the á/â selectivity at the anomeric carbon. To this end, we initially prepared N-tert-butoxycarbonyl-trans-4-hydroxy-L-proline allyl ester to be glycosylated by p-cresyl 2-O-benzyl-3,5-O-(di-tert-butylsilylene)-1-thio-á-L-arabinofuranoside, a conformationaly restricted donor developed for achieving high â-selectivity. Unfortunately, glycosylation with this donor led to complex mixtures and poor yields. Switching to the more robust 2,3,5-O-benzyl-1-thio-á-L-arabinofuranoside donor, we were able to obtain the Ara-Hyp monomer in 60% yield with 4:1 â:á selectivity using silver triflate and N-iodosuccinamide as activators. The â-Ara-Hyp monomer could be isolated by flash chromatography. A dimer of â-Ara-Hyp was prepared by deprotection of the N- and C- termini of the â-Ara-Hyp monomer respectively, after which peptide coupling of the two compounds was performed using HATU as coupling reagent to give the product, Boc-([â-L-Araf]Hyp)2-OAll, in 60% yield. Similar approaches were employed using a [2+1] or [1+2] fragment condensation strategy to produce the trimer, Boc-([â-L-Araf]Hyp)3-OAll, in 35% yield. The tetramer, Boc-([â-L-Araf]Hyp)4-OAll was produced using a [2+2] strategy in 49% yield. We’ve installed terminal amides on the oligomers to best mimic the extended peptide found in the natural allergen. Production of oligomer-specific building blocks (Ac-([â-L-Araf]Hyp)-OMe, Boc-([â-L-Araf]Hyp)-NHMe) allowed a more convergent synthesis towards the end-capped oligomers. With this strategy, end-capped dimer, trimer, and tetramer were synthesized by fragment condensation in 48%, 35%, and 15% respectively. The end-capped glycopeptides could then be fully deprotected by global debenzylation to give the final products in quantative yield. Circulardichroism spectra were obtained for the synthetic glycopeptides. Analysis of the CD spectra showed that the glycosylated proline oligomers exhibit a polyproline type II helical conformation. While CD spectrum of the monomer showed that it was unordered, the elliptical curve of dimer (ëmax = 220 nm, ëmin = 199 nm), trimer (ëmax = 222 nm, ëmin = 203 nm), and tetramer (ëmax = 220 nm, ëmin = 200 nm) all exhibited significant PPII characteristics. Nuclear…

▼ G-protein coupled receptors (GPCRs) form a superfamily of cell surface receptors with in excess of 2000 genes identified across taxa (Pierce et al., 2002). They are integral membrane proteins that are comprised of seven hydrophobic helical segments which form a transmembrane spanning bundle. Ste2p and Ste3p are Saccharomyces cerevisiae GPCRs that are the α-factor and a-factor pheromone receptors, respectively (Bardwell, 2005). Ste2p in particular has served as an excellent model for studying the mechanisms of action of GPCRs. Recent results suggest that the extracellular N-terminus of the Ste2p receptor is involved in modulating cell wall degradation and membrane juxtaposition during yeast mating potentially by mediating an intercellular interaction with Ste3p (Shi et al., 2009a).
The goals of this project were to obtain purified mg quantities of a soluble version of a portion of the N-terminus of Ste2p and to acquire structural information about this region by performing biophysical analysis on the soluble N-terminal Ste2p fragments. Initially, a synthetically produced KKK-Ste2p(14-43)-KKK peptide yielded circulardichroism (CD) spectra that indicated peptide secondary structure similar to what has been predicted in silico. Preliminary nuclear magnetic resonance (NMR) experiments with this peptide were also promising, yielding a correlation spectroscopy (COSY) spectrum that allowed for limited amino acid assignments. A recombinant version of the N-terminus of Ste2p, including residues 2-48 with terminal lysine residues, was expressed as a fusion protein in E. coli and the SK peptide was liberated by cyanogen bromide cleavage. Dynamic light scattering (DLS) analyses of the SK peptide showed it was aggregated when dissolved in water, but soluble in a trifluoroethanolamine/water (TFE/H2O) mixture. CD analysis of the SK peptide in TFE/H2O indicated that it contained more β-strand and less α-helix than the KKK-Ste2p(14-43)-KKK peptide. NMR analysis was performed on both an unlabelled and 15N-labelled SK peptide, yielding unusable spectra with very broad bands, most likely arising from aggregation at high concentrations. In conclusion, a high yield recombinant expression and purification system has been developed, yielding a Ste2p N-terminal peptide fragment that demonstrates some expected structural features. High resolution structural information may be obtained upon further optimization of the solvent system.
Advisors/Committee Members: Loewen, Michele C., Moore, Stan, Dmitriev, Oleg, Roesler, Bill, Campanucci, Veronica.

▼ Strongly-correlated electron materials reveal rich physics and exotic cross-coupled electronic and magnetic properties, with important fields results e.g. superconductivity and multiferroics. This is because of the competing interaction between charge, structure, and magnetism in the materials. In this dissertation I present a spectroscopic investigation of several model complex iron oxides under external stimuli of magnetic field, electric field, and temperature. The compounds of interest include NiFe2O4 [nickel ferrite], CoFe2O4 [cobalt ferrite], hLuFeO3 [hexagonal lutethium ferrite], and LuFe2O4 [lutethium ferrite]. These materials are attractive systems in the fields of multiferroics and high-temperature magnets for investigating optical band gap tunability, lattice and charge dynamics, spin-charge coupling, and optically-enhanced magnetoresistive effect. In these works, we have combined optical spectroscopy, magnetic circulardichroism (MCD), and (magneto-)photoconductivity, with high-quality thin-film growth, and first-principles calculations to reveal the nature of the optical excitations within these strongly correlated iron oxides. NiFe2O4 we found that optical excitations offer the opportunity for producing spin-polarized current. In CoFe2O4 we showed that the band gap is robust with temperatures up to 800 K. We found that the direct-gap excitation of LuFe2O4 is highly sensitive the strain induced by epitaxial growth.

► During the course of the thesis libraries of chiral (1,2)-diamines and prochiral 2,2’-biphenol derivatives were synthesised. The transfer of chirality from the diamine to the…
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▼ During the course of the thesis libraries of chiral (1,2)-diamines and prochiral 2,2’-biphenol derivatives were synthesised. The transfer of chirality from the diamine to the biphenol moiety mediated either by hydrogen bonding or coordination to a metal centre (ZnII, CuII) was demonstrated by CD (circular dicroism). The behaviour in solution of the hydrogen bonded complexes was investigated by NMR spectroscopy, UV-vis and ITC titrations (determination of association constants. The determination of absolute configurations of the ZnII complexes was achieved by X-ray structure determination and CD analyses both on the experimental and theoretical level. Last but not least, a new potentially catalytic phosphane ligand was derived from a dynamically racemic 2,2’-biphenol derivative.
Advisors/Committee Members: [email protected] (authoremail), false (authoremailshow), Vidal Ferran, Anton (director), true (authorsendemail).

► Point-of-care diagnostics for malaria currently rely on antibody-based rapid diagnostic tests (RDTs), but these tests are in danger of becoming obsolete as the world moves…
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▼ Point-of-care diagnostics for malaria currently rely on antibody-based rapid diagnostic tests (RDTs), but these tests are in danger of becoming obsolete as the world moves to eliminate malaria. More sensitive and robust techniques are needed to detect lower parasite loads using a more diverse array of biomarkers. This work encompasses several strategies to improve low-resource malaria diagnostics. First, a fluorescent on-bead sandwich detection method for PfHRP2 was developed that relies on a robust, stable transition metal compound rather than enzyme-tagged antibodies to produce signal. Then, circulardichroism was used to determine that heme binding causes the protein rcPfHRP2 to adopt a more helical structure than its typical unstructured form. This shift in structure also adversely affects the proteinâs ability to bind to antibodies on RDTs and in ELISAs. Work then transitioned to focus on DNA-based diagnostics due to the valuable information that DNA biomarkers can provide, and the large unmet need for point of care DNA diagnostic tests. Initial work focused on simplifying the DNA extraction process into an automated format, which was then expanded to include PCR in-line with the extraction to eliminate operator steps. Finally, a DNA-based RDT was developed to detect a âbarcodeâ DNA sequence, as part of the bio-barcode assay. This assay amplifies target DNA by hybridizing the captured target to a gold nanoparticle tagged with hundreds of barcode DNA sequences. When the barcode sequences are released, the signal from one target DNA strand is amplified to a level detectable by the RDT. This particular bio-barcode assay has issues with nonspecific binding, so unfortunately the two aspects of this assay were never combined with good results. However, the DNA-based RDT could be used as a platform for future work to bring DNA-based malaria diagnostics to low-resource settings.
Advisors/Committee Members: Raymond L. Mernaugh (committee member), David W. Wright (chair), David E. Cliffel (committee member), Janet E. Macdonald (committee member).

► Porous cellulose nitrate membranes were impregnated with 8CB and PCH5 LCs (liquid crystals) and separations of solutes dissolved in aqueous phases were performed while monitoring…
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▼ Porous cellulose nitrate membranes were impregnated with 8CB and PCH5 LCs (liquid crystals) and separations of solutes dissolved in aqueous phases were performed while monitoring solute concentration via UV-VIS spectrometry. The diffusing organic solutes, which consist of one aromatic ring and various functional groups, were selected to exclude molecular size effects on the diffusion and sorption.
We studied the effects on solute transport of solute intra-molecular hydrogen bonding and solute/LC intermolecular hydrogen bonding. Hydrogen-bonding effects are a significant factor in the permeation selectivity of positional isomers. The reduction of available hydrogen-bond donors in aromatic ortho-isomers due to intramolecular H-bonding resulted in significant differences in the diffusion relative to the para-isomers which possessed more available H-bond donors. Solutes possessing multiple H-bonding interactions experienced a higher barrier to diffusion and, consequently, lower diffusivities. Diffusing solutes with a single available H-bond donor exhibited faster diffusion than solutes without H-bond donors.
PCH5 embedded membranes showed higher solubility and diffusivity than the 8CB embedded membranes due to less dense molecular packing in PCH5 resulting from the bent cyclohexyl ring. The PCH5 LC membranes demonstrated enhanced permeation selectivity for hydroxybenzoic acid and aminophenol isomers primarily due to increased sorption selectivity. Shape selective absorption of rod-like para-isomers in the nematic phase was observed in both 8CB and PCH5 LCs.
A nonchiral based HPLC-CD (High Performance Liquid Chromatography-CD) system was developed for the characterization of enantioselective separations. An enantioselective cholesteric liquid crystal membrane was fabricated and evaluated using the nonchiral HPLC-CD system. The cholesteric LC membrane showed enantioselectivity in the cholesteric phase where activation energies of permeation for 1-phenylethanol enantiomers were significantly increased due to the increased interactions between enantiomer and LC phase. The enantioselectivity increased with decreasing pore size of the membrane and increasing chiral dopant compositions. The selectivity decreases when there are no hydrogen bonding interactions between enantiomer and chiral dopant.
Advisors/Committee Members: Martin, Stephen M. (committeechair), Madsen, Louis A. (committee member), Marand, Eva (committee member), Davis, Richey M. (committee member).

► Because of their unique optical properties, gold nanoparticles have potential applications in the construction of nanoscale optical and photonic devices that operate at length scales…
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▼ Because of their unique optical properties, gold nanoparticles have potential applications in the construction of nanoscale optical and photonic devices that operate at length scales below that of the diffraction limit of light. As an aid for the design of such devices, a phenomenological model was proposed and interaction mechanisms between gold nanoparticles, in the presence of an externally applied field, were investigated. A general equation of motion that governs the interaction mechanisms of the system was derived. The general equation of motion takes into account the radiation and intrinsic damping, coupling between induced dipoles and the applied field, and the induced dipole-dipole coupling. The dependence of the damping constants and the coupling parameters on the size of the gold nanoparticle was investigated. The dispersion relations for chirally arranged gold nanoparticles was calculated numerically and analytically. The optical properties of metallic nanoparticles arranged in a chiral structure were also studied. Circulardichroism (CD) and optical rotary dispersion (ORD) were calculated numerically for various numbers of gold nanoparticles. The CD extinction coefficient as a function of wavelength was obtained for a chiral structure with four nanoparticles per turn. The ORD coefficient as a function of wavelength was calculated for chiral structures with four and six nanoparticles per turn. The numerical results have revealed that a chiral structure with six nanoparticles per turn, compared with a structure with four nanoparticles per turn, yields much stronger ORD signals even if it has a smaller number of gold nanoparticles.

► Chapter one provides an introduction to the general area of study and the general basis for the research to be performed. It concludes with a…
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▼ Chapter one provides an introduction to the general area of study and the general basis for the research to be performed. It concludes with a brief mathematical description of the computational equations used to calculate and measure vibrational circulardichroism (VCD).Chapter two evaluates four chemically related compounds and provides detailed analyses of the vibrational spectra obtained by performing a combination of experimental and theoretical chemical techniques. For 1,4-dithiane the ground state was found to possess C2h symmetry. A high energy form of 1,4-dithiane possessing D2 was also discovered. At the ground state, 1,4-thioxane was found to posses C2 symmetry. Two high energy forms of 1,4-thioxane possessing C1 and C2 symmetries were found using quantum chemical techniques. For di-vinyl sulfoxide, the ground state was found to posses CS symmetry. Three high energy forms of di-vinyl sulfoxide were found possessing CS, C’1 and C’S symmetries using quantum chemical techniques. The theory predicts di-vinyl sulfone to posses C2 symmetry in the ground state. This compound was found to possess two high energy forms with CS and C1 symmetries using quantum chemical techniques.For all compounds, a detailed thermodynamic analysis was performed. Enthalpies, entropies and free energy were derived and compared. It is concluded, both MP2 and DFT/B3LYP yield a good description of the vibrational modes and thermodynamics for the compounds researched.For chapter three, a detailed analysis of α-d-alanine, α-l-alanine, β-l-mannose and α-l-mannose were performed using a combination of experimental and theoretical techniques. Assignments for alanine were compared to the purely theoretical study performed by Tajkhorshid and coworkers. It was determined that alanine as a zwitterion hydrogen bounded to four water molecules is the lowest energy conformer. In water (pH 6.5) amide I bands are not observed. Potassium bromide presses (KBr-pellets) for α-dalanine, α-l-alanine and α-l-mannose compared favorably with literature. Computational VCD spectra differed with theoretical results suggesting a need for the proper damping function to treat the results thus improving agreement between computational and experimental data. It is concluded, DFT/B3LYP yields a good description of the VCD for α-d-alanine, α-l-alanine, β-l-mannose and α-l-mannose.Chapter four presents, the first time, VCD for several compounds. Five of the compounds have never before been synthesized. These compounds were measured to determine environmental effects at and around the chiral (stereo) center. It was determined for the first time that the electron influence on the chiral center can be recorded in the VCD. Results warranted the measurement of 25+ additional compounds in an effort to better understand observations from the initial measurements.Experimental data supports the general conclusion “electron-donating groups intensify the VCD signal by forcing conjugation or electron cloud contribution towards the chiral center.” Electron withdrawing groups weaken the…
Advisors/Committee Members: Kay, Jack G..

► The baculovirus AcMNPV early/late gene me53 is required for efficient BV production and is conserved in all alpha and betabaculoviruses. The 449-amino acid protein contains…
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▼ The baculovirus AcMNPV early/late gene me53 is required for efficient BV production and is conserved in all alpha and betabaculoviruses. The 449-amino acid protein contains several highly conserved functionally important domains including two putative C4 zinc finger domains (ZnF-N and ZnF-C) whose cysteine residues are 100% conserved. One purpose of this study is to confirm the presence of two zinc binding domains in ME53, as well as determine their role in virus infection and viral gene transcription. Interestingly, deletion of ZnF-C results in an early delay of BV production from 12 to 18 hours post transfection correlating to ME53's cytoplasmic localization. Cytoplasmic functions at early times post-transfection may include translational regulation, which is supported by yeast-2-hybrid data that ME53 interacts with the host 40S ribosomal subunit protein RACK1. In this study the association of ME53 with the ribosomes of virus infected cells was also investigated.
Advisors/Committee Members: Krell, Peter (advisor).

Ralph, R. (2018). Characterization of Autographa californica nucleopolyhedrovirus immediate early protein ME53: The role of conserved domains in BV production, viral gene transcription, and evidence for ME53 presence at the ribosome
. (Thesis). University of Guelph. Retrieved from https://atrium.lib.uoguelph.ca/xmlui/handle/10214/14678

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ralph, Robyn. “Characterization of Autographa californica nucleopolyhedrovirus immediate early protein ME53: The role of conserved domains in BV production, viral gene transcription, and evidence for ME53 presence at the ribosome
.” 2018. Thesis, University of Guelph. Accessed May 25, 2019.
https://atrium.lib.uoguelph.ca/xmlui/handle/10214/14678.

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ralph, Robyn. “Characterization of Autographa californica nucleopolyhedrovirus immediate early protein ME53: The role of conserved domains in BV production, viral gene transcription, and evidence for ME53 presence at the ribosome
.” 2018. Web. 25 May 2019.

Vancouver:

Ralph R. Characterization of Autographa californica nucleopolyhedrovirus immediate early protein ME53: The role of conserved domains in BV production, viral gene transcription, and evidence for ME53 presence at the ribosome
. [Internet] [Thesis]. University of Guelph; 2018. [cited 2019 May 25].
Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/14678.

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ralph R. Characterization of Autographa californica nucleopolyhedrovirus immediate early protein ME53: The role of conserved domains in BV production, viral gene transcription, and evidence for ME53 presence at the ribosome
. [Thesis]. University of Guelph; 2018. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/14678

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation